Processes are already known for examining a medium so as to pinpoint therein reflecting targets and/or for destroying the targets, using the temporal reversal of the signals received by the piezoelectric transducers of an array, before reemission (document EP-A-0 383 650).
Such processes perform a focusing of energy on a target, that is to say a spatial compression of energy.
The present invention is aimed in particular at carrying out, in addition to spatial compression by focusing, temporal compression of energy.